Police ring Barbican building site . More than 100 City police faced hundreds of building trade workers at the trouble - torn Barbican site today . The Police were there to prevent trouble as Myton, the contractors , tried to resume work on its multi - million pound building site . The firm was bringing in a newly recruited labour force , despite threats that they will not be allowed to cross the picket line . Photo shows ; Police and placard carrying pickets outside the Barbican site today . 16 October 1967